Patent DE-102009025182-A1 (DE)
Title: Optical beam expander for laser material processing, comprises sockets, which hold coated lens and are connected with one another, elastic elements, adjusting rings having internal thread sections, guide grooves, and connection channels
Inventor: FLECK ADOLF
IPC: B23K26/06
Filed: 2009-06-12
Abstract: The optical beam expander (1) comprises first, second and third sockets (2, 4, 5), which hold a coated lens and are connected with one another, so that the first and second sockets and the second and third sockets are displaceable relative to each other in longitudinal direction of the beam expander to change the distance of the coated lenses (3, 5, 7) hold by the respective sockets, a first elastic element (17), which is connected to the first or second sockets to improve clearance fit present between the first and second sockets, and a second elastic element (25). The optical beam expander (1) comprises first, second and third sockets (2, 4, 5), which hold a coated lens and are connected with one another, so that the first and second sockets and the second and third sockets are displaceable relative to each other in longitudinal direction of the beam expander to change the distance of the coated lenses (3, 5, 7) hold by the respective sockets, a first elastic element (17), which is connected to the first or second sockets to improve clearance fit present between the first and second sockets, a second elastic element (25), which is connected to the second or third sockets to improve clearance fit present between the second and third sockets, a first adjusting ring having a first internal thread section and a second internal thread section, which cooperate with respective external thread sections of the first and second sockets, so that the both sockets are moved apart from each other during rotation of the first adjusting ring in a first rotational direction and are moved to each other during rotation of the first adjusting ring in a second rotational direction, a first guide groove extending from the first and second sockets in a longitudinal direction of the beam expander, a second adjusting ring having a first internal thread section and a second internal thread section, which cooperate with respective external thread sections of the second and third sockets, so that the both sockets are moved apart from each other during rotation of the second adjusting ring in a first rotational direction and are moved to each other during rotation of the second adjusting ring in a second rotational direction, and a second guide groove extending from the second and third sockets in the longitudinal direction of the beam expander. The first and second internal thread sections of the first adjusting ring are formed as left-hand thread and right-hand thread respectively. The first and second internal thread sections of the second adjusting ring are formed as right-hand thread and left-hand thread respectively. The first and/or second elastic element is formed as O-ring, which fits in an annular groove of the respective sockets. The sockets are connected with one another, so that rotation of one socket to other socket does not take place during displacing two sockets to each other. A first guide pin stands in the first guide groove and is connected with the first and second sockets to prevent the rotation of the first and second sockets to each other. A second guide pin stands in the second guide groove and is connected with the second and third sockets to prevent the rotation of the second and third sockets to each other. A controllable change of the divergence of the beams passing through the lenses takes place by changing the distance of the lenses. The beam expander is designed for the wavelength of 355 nm, 532 nm or 1064 nm. A stepless displacement of the sockets to each other is possible in the beam expander. A first connection channel is provided between the first and second sockets for pressure balance between the internal chambers of the both sockets. A second connection channel is provided between the environment and the first or third sockets for pressure balance between the internal chambers of the first or third sockets and the environment. An independent claim is included for a method for processing materials by using a laser.